Injection machine for wicking material

ABSTRACT

A bearing is clamped and held in position by a machine during operation of the machine. The machine reliably injects a metered amount of a lubricant impregnated wicking material into an annular cavity surrounding the bearing. The lubricant impregnated wicking material is injected into the bearing annulus by a plurality of injectors and enters the bearing annulus through a plurality of courses. The bearing annulus is thus completely filled with uniformly lubricated wicking material. Additionally, the injection machine moves the lubricant impregnated wicking material in a manner to preclude agglutination of the material at any point within the machine.

United States Patent [191 Hollowell Nov. 27, 1973 INJECTION MACHINE FOR WICKING 3,601,164 8/1971 Bruce 222/334 X MATERIAL i'iii'fiii $11325 i ifi 345313 eyno s [75] Inventor: Roger T. Hollowell, Owosso, Mich.

[73] Assignee: Permawick Company, Inc., Detroit, Primary ExaminerJohn Petrakes Mich. Assistant Examiner-Frederick R. Schmidt Filed p 26 1971 Attorneyl ,ane, Aitken, Dunner & Ziems [21] Appl. N0.: 137,504 [57] ABSTRACT A bearing is clamped and held in position by a ma- 52 US. Cl. 184 1 D 141 258, 222 334, 1 264/269 264/329 6 417/521 4250244 chine during operation of the machlne. The machine 5 I t Cl F01 U00 11/02 reliably injects a metered amount of a lubricant imi i m 141/100 T 99 pregnated wicking material into an annular cavity surl41/284 rounding the bearing. The lubricant impregnated 334 361 269 329. 417/33 wicking material is injected into the bearing annulus by a plurality of injectors and enters the bearing annulus through a plurality of courses. The bearing annulus is thus completely filled with uniformly lubricated [56] Refe'mes c'ted wicking material. Additionally, the injection machine UNITED STATES PATENTS moves the lubricant impregnated wicking material in a 3,268,638 8/1966 Tann 264/269 X manner to preclude agglutination of the material at 3,52,;2; et al. any point within the machine.

lS 3,431,953 3/1969 Rutherford 222/334 X 10 Claims, 10 Drawing Figures PAIENIEU um 27 I975 SEEZT 12F 1 v 1 ls INVENTOR ROGER T HOLLOWELL q w,

ATTORNEYS 1 INJECTION MACHINE FOR WICKING MATERIAL BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an improved injection machine and more particularly to one having improved means for accurately metering the quantity of a material injected during operation of the machine, and completely filling bearing cavities of complicated cross section.

2. Description of the Prior Art Frequently, it has become necessary to inject a lubricant impregnated wicking material into wick fed sleeve bearing reservoirs which contain restricted passageways. To ensure a filling of the entire reservoir without any voids, the lubricant impregnated wicking material has'been injected under pressure. As noted in the Patent to Tann, U.S. Pat. No. 3,268,638 which issued Aug. 23, 1966 and is assigned to the same assignee as the present invention, the lubricant is a bearing oil which has a tendency to separate from the wicking material when the material is subjected to high pressures. A number of methods have been devised to prevent the separation. The method suggested in the abovementioned Tann patent was to expose the oil impregnated wicking material to vibration as it was being injected. It was found that this vibration enabled use of an increased injection pressure without separation thereby permitting the filling of reservoirs containing somewhat restricted passageways.

As the design of the bearing support changed, the passageways between adjacent reservoir portions became more restricted. The injection pressures required to properly fill such a reservoir tended to cause a separation of the lubricant from the wicking material. The previously tried methods of maintaining the mixture in its combined form became unsatisfactory.

Further, it was possible to operate the injection machines of the prior art so as to unintentionally partially till a bearing reservoir.

SUMMARY OF THE INVENTION The injection machine of the present invention makes it possible to inject lubricant impregnated wicking material so as to fill bearing reservoirs of constricted construction without the lubricant separating from the wicking material. This is accomplished with injection pressures which are below those at which a separation of the lubricant from the wicking material will occur.

An object of the present invention is to reduce the injection pressure required to fill chambers interconnected by narrow passageways with a lubricant impregnated wicking material so that the material will not separate upon injection.

It is another object of the present invention to provide an injection and metering device which is capable of rapidly and completely filling chambers interconnected by narrow passageways.

It is a further object of the present invention to provide a machine of the above-mentioned type which will not operate unless it is in condition to deliver a predetermined metered amount of lubricated wicking material.

Further objects and advantages of the present invention will become apparent and the exact nature of the invention will be clearly understood when the following description is considereed in conjunction with drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation, partially in section and partially broken away, of the subject invention.

FIG. 2 isa perspective view of the injection and metering block of FIG. 1 showing inlet and outlet tubing connected thereto.

FIG. 3 is a section view through the block taken along line 3-3 of FIG. 2.

FIG. 4 is a front elevation, partially in section, of the block showing a metered amount of lubricant impregnated wicking material in place.

FIG. 5 is a front elevation, partially in section, of the block showing the nozzle in position for clamping a workpiece.

FIG. 6 is a front elevation, partially in section, of the block after the lubricant impregnated wicking material has been injected.

FIG. 7 is a front elevation, partially in section, of the block after injection and prior to refilling with wicking material.

FIG. 8 is a front view of the injection piston showing the limit switches and their actuators.

FIG. 9 is a plan view of a workpiece usable with the subject invention showing four ribs supporting a bearmg.

FIG. 10 is a sectional view through the workpiece of FIG. 9 taken along line 10l0.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates the injection machine 10 of the present invention which includes a housing 12 upon which is mounted a hopper 14 which contains a suitable amount of lubricant impregnated wicking material comprising a mixture of a bearing oil and small fibers of wicking material as described in the aforementioned U.S. Pat. No. 3,268,638. The hopper 14 has an inclined bottom l6which slopes inwardly to a downwardly extending cylindrical portion 18 which projects through an opening 20 in the housing 12. Within the downwardly extending cylindrical portion 18 of the hopper 14 is a vertically disposed auger 22 mounted on a shaft 24 extending downwardly into the housing 12 and driven in common with a pump mechanism 26 mounted in the housing 12 directly below the hopper 14. At its upper end the auger 22 carries an agitator rod 28 mounted thereon in a suitable manner for constantly agitating the material within the hopper 14 during rotation of the auger 22.

The pump mechanism 26 may be of any suitable type, for example the type disclosed in my copending application Ser. No. 128,074 filed on Mar. 24, 1971, the structure of which is best shown in FIG. 3 of that application and the operation of which is disclosed therein. Briefly however, the pump mechanism 26 and the shaft 24 are driven by a motor, not shown, which supplies the energy necessary to advance the wicking material from the hopper 14 out through a discharge passage 30 to a discharge line 32. The action of the pump mecahnism 26 urges the wicking material through the discharge line 32 and delivers it under pressure to a metering and injection mechanism 34.

Referring to FIGS. 1, 2 and 3 the metering and injection mechanism 34 includes a block 36 of substantially rectangular cross section, as can be best seen in FIG. 3, immovably attached to a plate 38 which in turn is attached to the injection machine 10. The block 36 has two cylindrical passageways 40 and 42 extending longitudinally therethrough. The centers of the passageways 40 and 42 are located on the longitudinal axis of symmetry of the cross section of the block 36 with each center in close proximity to a short side of the block 36. A pair of studs 44 and 46 are slidably supported in the block 36 by the cylindrical passageways 40 and 42. The upper ends of these the studs 44 and 46 are fixed to a plate 48 by pins 50 and 52. The plate 48 forms the lower portion of an injection cylinder 54. At their lower ends studs 44 and 46 are interconnected by a plate 56. The plate 56 is locked in position against studs 44 and 46 respectively by nuts 62 and 64.

An upper plate 66 of the injection cylinder 54 is attached to a piston rod 68 of a double-acting air cylinder 70. The outer portion of the cylinder 70 is attached to the upper portion of the plate 38 and is supplied with air from a source not shown through air inlets 72 and 74. A piston 130 is attached to the upper portion of the piston rod 68 to be acted upon by the air entering through either of the inlets 72 or 74.

Four cylindrical metering and injection passageways 76 extend longitudinally through the block 36. These four cylindrical metering and injection passageways 76 are spaced equidistant from one another and the group of four is located so that the center of a square which may be drawn with its corners at the cylinders centers lies upon the longitudinal axis of symmetry of the cross section of the block 36 with the squares sides parallel to the sides of the block 36. The center of said square lies midway between the cylindrical passageways 40 and 42. Within each of the cylindrical metering and injection passageways 76, approximately two-thirds of the way down from the upper surface of the block 36 is the upper portion of a cylindrical recess 78 which is concentric with each of the cylindrical passageways 76, as may be best seen in FIGS. 4-7. The recesses 78 increase the volume of the passageways 76 for their extent which is limited to approximately ten percent of the length of the block 36. Slidably supported by the upper portions of the cylindrical metering and injection passa eways 76 are four injection pistons 80. The injection pistons 80 in the position illustrated in FIG. 1 engage a plate 84 at their upper ends which plate 84 is in turn secured to a piston rod 86. The piston rod 86 is attached at its upper end to an injection piston 88 within the injection cylinder 54.

Slidably supported within the lower portion of each of the cylindrical passageways 76 is a delivery rod 90. Each delivery rod 90 has an axial passageway 92 which begins at the lower end thereof and extends within the rod to a point which is a specific distance from a solid upper portion 94 thereof. This specific distance is approximately equal to the height of the cylindrical recesses 78. Located on the circumference of each delivery rod 90 at its upper end are at least two orifices 96 the openings on the circumference of which begin a distance from the upper end thereof somewhat less than the height of the recesses 78. These orifices 96 which communicate at their inner ends with the axial passageways 92 forming an acute angle therewith. The lower end of the delivery rods 90 are secured to the lower plate 56 which plate is attached to an upper portion 98 of an injection nozzle 100.

The upper portion 98 of the nozzle 100 is attached to a lower portion 102 of the nozzle 100. Within this lower portion of the nozzle 100 are four outlet passages 104 which exit from the nozzle 100 at an acute angle to the lowest portion 106 thereof. The outlet passageways 104, at their upper ends, communicate with the lower ends of the passageways 108 which extend through the upper portion 98 of the nozzle 100. These passageways 108 are angled within the portion 98 of the nozzle 100 so that their upper ends are in communication with the lower ends of passageways 110 within the plate 56. The upper ends of the passageways 110 communicate with the lower ends of the passageways 92. It can thus be appreciated that four independent outlet passageways 104 communicate with the four delivery passageways 92.

As the discharge line 32 approaches the block 36 it bifurcates into two branches 112 each of which communicates with an inlet passageway 114 located closer to the upper portion of the block 36 than to its lower portion at a point approximately one-third of its length from the top. Each inlet passageway 114, as best shown in FIG. 3, communicates with two of the four metering and injection passageways 76 through cross-drilled passageways 1 16. These passageways 116 enter the metering and injection passageways 76 and form inlet orifices 118 therein. The studs 44 and 46, their attachment to both the lower plate 56 and the upper plate 48 and the relationship of the assemblage to the cylinder 70 is such that the solid upper portion 94 of the delivery rod 90 assumes a definite posture within the passageways 76. This posture is such that the solid upper portion 94 rises within each of the injection passageways 76 to a point coincident with the lower portion of the inlet orifices 118 when the metering and injection mechanism is in its completely retracted position as shown in FIGS. 4 and 7.

Also within each of the injection passageways 76 is an outlet orifice 120 spaced a distance above inlet orifices 118 so as to define within each injection passageway 76 a volume therebetween equal to one-fourth of the total volume of wicking material sought to be injected. The lower ends 122 of the injection pistons 80 are chamferred and in their uppermost position, as illustrated in FIG. 4, the lower portions 122 extend within the injection passageways 76 to a depth such that each of the lower portions 122 abut the upper portions of the outlet orifices 120. The outlet orifices 120 each communicate with a return conduit 124 through separate passageways 126. The conduit 124 is attached to the upper portion of the hopper 14. It should be noted that there is no intersection between the centerline of the inlet passageways 116 and the centerline of the passageways 76. On the other hand, the intersection between the centerline of the passageways 76 and the centerline of the outlet orifice 120 does occur. The result of the geometry of these intersections is such that, as may be best seen in FIG. 3, the inlet orifices 118 have a greater cross-sectional area than the outlet orifices 120.

The operation of the injection machine is begun by pushing the switch 128 to start the motor, not shown, a suitable amount of the lubricant impregnated wicking material having been placed in the hopper 14. After a short initial period of operation, the pump mechanism 26, operating as disclosed in my aforementioned copending application fills the discharge line 32 to which it is Connected. The wicking material, under pressure from the pump mechanism 26, enters the injection passageways 76 through the inlet orifices 118 assuming that the piston 130 within the cylinder 70 and the attached apparatus is in its uppermost position. As the wicking material enters through the inlet orifices 118 the pressure of the incoming wicking material forces the injection pistons 80 to their uppermost position, or maintains them in that position, within the injection passageways 76. A constant movement of the wicking material within the space defined between the injection pistons 80 and the delivery rods 90 takes place as the wicking material exits back to the hopper 14 through the outlet orifices 120. As the outlet orifices 120 are smaller in cross-sectional area than the inlet orifices 118 the reduction in cross-sectional area acts as a constriction and requires a predetermined pressure to be exerted on the wicking material to cause it to flow through the conduit 124 and back into the hopper 14. Consequently, if the pressure within the discharge line 32 or metering chambers defined between the injection pistons 80 and delivery rods 90 exceeds this predetermined pressure the wicking material will simply pass through the conduit 124 and back into the hopper 14. When the auger 22 delivers more wicking material than is required, this excess material will also recirculate through the conduit 124 and back into the hopper 14.

An electric motor end bracket 132 is placed in position on a fixture 133 on a table 134 of the machine 10. A control 136 is operated to swtch the supply of air to the cylinder 70, from a source not shown, from the inlet 74 to the inlet 72. The air enters the upper portion of the cylinder 70 and moves the piston 130 and its attached apparatus downward. Part of the attached apparatus which moves downward is the injection cylinder 54 which has attached thereto the studs 44 and 46. As

the studs 44 and 46 move downward, the plate 56 which is attached to the studs 44 and 46 moves downward as well to clamp the motor end bracket 132 onto the fixture 133 on the table 134 in preparation for injection of the wicking material. The metering and injection mechanism 34 has now assumed the position illustrated in FIG. 5. I

' As noted above, the injection pistons 80 engage the plate 84 which is in turn secured to the piston rod 86. The downward movement of the piston 130 therefore causes the injection pistons 80 to slide downward within the injection passageways 76. As the delivery rods 90 are attached to the plate 56, the injection pistons 80 and delivery rods 90 move as a unit to the position illustrated in FIG. 5 with the wicking material entrapped therebetween. In this position, the inlet orifices 96 in the delivery rods 90 are within the recesses 78 and the entrapped wicking material no longer communicates with the inlet orifices 118 and outlet orifices 120.

Attached to the upper portion 66 of the injection cylinder 54 is an actuator arm 139 which moves downward with the cylinder -54. When the cylinder 54 reaches its lowest position a limit switch 140, is actuated to supply a signal which causes air to be supplied to the injection cylinder 54 through an inlet 142.

As the air enters the cylinder 54 through the inlet 142 it moves the injection piston 88 and associated apparatus downward. This moves the pistons 80 within the passageways 76 and forces the entrapped wicking material into the recesses 78. Continued movement of the injection pistons results in substantially the entire amount of wicking material contained between the pistons 80 and the rods to enter the recesses 78 and, through the orifices 96, the passageways 92. The pressure acts on the material within the passageways 92 to force it through passageways in the plate 56 and finally through the outlet passages 104 of the injection nozzle. Assuming that all of these passageways are filled, the result of this movement of wicking material is a deliverance, at the injection nozzle 100, of the metered amount of wicking material from the four outlet passages 104 into the four interconnected chambers of a bearing reservoir 144 of the clamped-in-position motor end bracket 132. The bearing reservoir 144 may thus be completely filled despite a complex cross section as shown in FIGS. 9 and 10 without requiringan injection pressure which would cause separation of the lubricant from the wicking material.

When the injection piston 88 has moved to its lowest position and the pistons 80 have injected the metered amount of wicking material, the metering and injection mechanism 34 assumes the position illustrated in FIG. 6. With the exception of a small amount of wicking material which remains between the chamfer of the pis tons 80 and the top 94 of the rod 90 which will be injected during the next operation of the machine, all of the entrapped wicking material has been advanced to inject the metered amount of wicking-material into the reservoir 144.

When the injection piston 88 reaches the bottom of its travel an actuator 158 attached to the plate 84'actuates a switch 148. The actuation of the switch 148 causes a signal to be sent to a solenoid, .not shown, which operates to switch the air from the air inlet 72 to the air inlet 74. This causes the piston and its attached apparatus to move upward and once again assume the position shown in FIGS. 1 and 2.

The upward movement of the plate 56 moves the delivery rods 90 upward to their fully retracted position. The chamferred ends 122 of the injection pistons 80 abut the tops 94 of the delivery rods 90 and are driven up as well. Asmay be seen in FIG. 7 the chamferred ends 122 of the injection pistons 80 are, in this position, in registration with the inlet orifices 118. The pressure placed on the wicking material within the discharge line 32 by the pumping mechanism 26 forces the wicking material around the chamfers and raises the injection pistons 80 to the position indicated in FIG. 4. This movement of the injection pistons 80 continues until upper ends thereof engage the plate 84 at which point the outlet orifices 120 are uncovered and the aforementioned circulation of the wicking material back to the hopper 14 takes place. Attached to one of the injection pistons 80 nearest the plate 38 is an actuator arm 150. This arm 150 rises with the piston 80 it is attached to as the passageway fills with wicking material. When the cavity between the piston 80 and the rod 90 is filled, the arm 150 actuates the switch 152 to produce a signal which is directed to partially enable the control 136. Attached to the other injection piston 80 nearest the plate 38 is another actuator arm 156. This arm 156 also rises with the piston 80 it is attached to as the passageway fills with wicking material. When that cavity between the piston 80 and the rod 90 is filled, the arm actuates a switch 154 to produce a signal which is directed to the control 136. The receipt of this second signal completed the enablement of the control 136 and permits it to be actuated by the operator to repeat the next clamping and injection cycle. The requirement of the receipt of two enabling signals insures that the bifurcations 112 of the supply line 32 are not blocked and that at least two and probably four of the chambers have been properly filled with wicking material. If desired, additional actuator arms and switches could be added and enablement of the control 136 be made dependent upon receipt of a signal from each of the switches.

It will be readily appreciated that an adjustment of the amount of wicking material injected may be accomplished by adjustment of the height of the actuator 158 which will affect the length of stroke of the injection pistons 80 due to the actuation of the limit switch 148. In this manner less than a total amount of wicking material between the injection pistons 80 and the delivery rods 90 may be injected into the bearing reservoir 144. Any wicking material which remains in the cavity will be injected during subsequent operation of the machine. Naturally, the maximum amount of wicking material is determined by the distance between the inlet orifices 118 and the outlet orifices 120. Additionally, the interruption of the constant flow of wicking material only during the actual injection operation, combined with the aforementioned design features, serves to prevent small amounts of the wicking material from being trapped at any point within the machine for prolonged periods to impede the flow of the remainder of the wicking material through the machine. Further, the design of the machine which effectively prevents operation unless the desired metered amount is present within the machine for extrusion through the four-part injection nozzle 100 prevents operation of the machine so as to unintentionally partially fill bearing reservoirs.

. While one specific embodiment of the present invention has been illustrated and has been described in detail herein, it would be readily appreciated to those skilled in the art that numerous modifications and changes may be made without departing from the spirit and scope of the present invention.

What is claimed is:

1. An improved machine capable of injecting a lubricant-impregnated wicking material into a bearing reservoir having a plurality of reservoir portions, said machine being of the type that includes a source of lubricant-impregnated wicking material, injection means for injecting said material into said bearing reservoir, and delivery means for advancing said material from said source to said injection means, the improvement comprising a plurality of chambers in said injection means for accumulating a plurality of metered amounts of said material prior to injection, a plurality of outlet orifices adapted to communicate said chambers with said reservoir portions so that each of said metered amounts of material will be injected into a reservoir portion, piston means cooperating with each of said chambers for forcing said metered amounts of said material through said orifices and into said reservoir portions when moving from a back position toward a forward position relative to said chamber, moving means for moving said piston means toward said forward position relative to said chambers, actuating means cooperating independently with at least two of said chambers for actuating said moving means after a metered amount of said material has accumulated in chambers with which said actuating means is cooperating.

2. The improvement in claim 1, wherein at least two of the piston means are adapted to move independent of each other from said forward position toward said back position when said material is advanced into said chambers, and said means for actuating actuates said moving means after at least two of said independently movable piston means reach said back position.

3. The improvement in claim 1 where said delivery means passes all material which enters said chambers progressively therethrough back to said source after said chambers are filled, and said injection means temporarily interrupts said progressive flow of material through said chambers while injecting said material into said reservoir portions.

4. The improvement in claim 1 wherein said injection means comprises: a housing; a plurality of passageways disposed longitudinally within said housing; a cooperating piston means and rod slidably supported within each of said longitudinal passageways; said moving means includes means for cycling said cooperating piston means and rods to said first, second, and third positions; in said first position the adjacent ends of each cooperating piston means and rod being in spaced apart relation to define a chamber therebetween within each of said longitudinal passageways communicating with said delivery means; in said second position each cooperating piston means and rod being shifted to move said chambers out of communication with said delivery means; and in said third position, each piston means being advanced toward its respectively cooperating rod to eject the metered amount of material from each chamber.

5. The improvement in claim 4 wherein said cycling means includes control means for automatically cycling said cycling means from said first position to said second and third positions and back to said first position, said control means automatically deactivating said cycling means when said piston means and rods return to said first position.

6. The improvement in claim 4 wherein each of said rods contains discharge passageway means therein; and each of said longitudinally disposed passageways is adapted to communicate each of said chambers with the discharge passageway means of the rod associated therewith when said cooperating piston means and rods are in said second and third positions.

7. The improvement in claim 4 wherein said means for cycling includes means to cycle said cooperating piston means and rods to a fourth position; in said fourth position said cooperating piston means and rods engaging one another and communicating with said delivery means to enable wicking material to flow under pressure between the adjacent ends of said cooperating piston means and rods to urge said piston means to said first position.

8. The improvement in claim 7 wherein said cycling means includes control means for automatically cycling said cycling means from said first position to said second, and third positions with the wicking material under pressure operating to return all of said piston means to said first position.

9. The improvement in claim 8 wherein said control means includes said actuating means for actuating said cycling means only when a metered amount of wicking material has accumulated in each chamber.

10. The improvement in claim 9 wherein said injection means includes means for clamping a workpiece in position for said injection in said second position; and said control means includes means for initiating cycling to said third position in response to completion of said clamping; and means for initiating cycling to said fourth position in response attainment of said third position. 

1. An improved machine capable of injecting a lubricantimpregnated wicking material into a bearing reservoir having a plurality of reservoir portions, said machine being of the type that includes a source of lubricant-impregnated wicking material, injection means for injecting said material into said bearing reservoir, and delivery means for advancing said material from said source to said injection means, the improvement comprising a plurality of chambers in said injection means for accumulating a plurality of metered amounts of said material prior to injection, a plurality of outlet orifices adapted to communicate said chambers with said reservoir portions so that each of said metered amounts of material will be injected into a reservoir portion, piston means cooperating with each of said chambers for forcing said metered amounts of said material through said orifices and into said reservoir portions when moving from a back position toward a forward position relative to said chamber, moving means for moving said piston means toward said forward position relative to said chambers, actuating means cooperating independently with at least two of said chambers for actuating said moving means after a metered amount of said material has accumulated in chambers with which said actuating means is cooperating.
 2. The improvement in claim 1, wherein at least two of the piston means are adapted to move independent of each other from said forward position toward said back position when said material is advanced into said chambers, and said means for actuating actuates said moving means after at least two of said independently movable piston means reach said back position.
 3. The improvement in claim 1 where said delivery means passes all material which enters said chambers progressively therethrough back to said source after said chambers are filled, and said injection means temporarily interrupts said progressive flow of material through said chambers while injecting said material into said reservoir portions.
 4. The improvement in claim 1 wherein said injection means comprises: a housing; a plurality of passageways disposed longitudinally within said housing; a cooperating piston means and rod slidably supported within each of said longitudinal passageways; said moving means includes means for cycling said cooperating piston means and rods to said first, second, and third positions; in said first position the adjacent ends of each cooperating piston means and rod being in spaced apart relation to define a chamber therebetween within each of said longitudinal passageways communicating with said delivery means; in said second position each cooperating piston means and rod being shifted to move said chambers out of communication with said delivery means; and in said third position, each piston means being advanced toward its respectively cooperating rod to eject the metered amount of material from each chamber.
 5. The improvement in claim 4 wherein said cycling means includes control means for automatically cycling said cycling means from said first position to said second and third positions and back to said first position, said control means automatically deactivating said cycling means when said piston means and rods return to said first position.
 6. The improvement in claim 4 wherein each of said rods contains discharge passageway means therein; and each of said longitudinally disposed passageways is adapted to communicate each of said chambers with the discharge passageway means of the rod associated therewith when said cooperating piston means and rods are in said second and third positions.
 7. The improvement in claim 4 wherein said means for cycling includes means to cycle said cooperating piston means and rods to a fourth position; in said fourth position said cooperating piston means and rods engaging one another and communicating with said delivery means to enable wicking material to flow under Pressure between the adjacent ends of said cooperating piston means and rods to urge said piston means to said first position.
 8. The improvement in claim 7 wherein said cycling means includes control means for automatically cycling said cycling means from said first position to said second, and third positions with the wicking material under pressure operating to return all of said piston means to said first position.
 9. The improvement in claim 8 wherein said control means includes said actuating means for actuating said cycling means only when a metered amount of wicking material has accumulated in each chamber.
 10. The improvement in claim 9 wherein said injection means includes means for clamping a workpiece in position for said injection in said second position; and said control means includes means for initiating cycling to said third position in response to completion of said clamping; and means for initiating cycling to said fourth position in response attainment of said third position. 